Natural Resources, School of


Date of this Version



Published in Proceedings of the Nebraska Academy of Sciences and Affiliated Societies, 89th Annual Meeting, April 20–21, 1979, p. 49.


Copyright © 1979, Robert F. Diffendal, Jr.


The Mitchell Pass Member of the Gering Formation was defined by Vondra, Schultz, and Stout in 1969 on the basis of exposures in the Wildcat Ridge area of western Nebraska. The basal part of the member in many areas of Wildcat Ridge is a pumice-pebble conglomerate bed. A newly discovered pumice-pebble conglomerate locality occurs north of Broadwater, Nebraska, some twenty miles east of the easternmost previously reported exposure of the pumice conglomerate at Redington Gap on Wildcat Ridge. Pumice samples from Redington Gap and Broadwater have the same index of refraction and similar inclusions. Beds above the conglomerate and below the Monroe Creek Formation at Broadwater have yielded fossil oreodonts typical of the Gering Formation. This evidence tends to support suggestions by Stout that the exposures north of Broadwater are an eastern continuation of at least part of the Gering Formation into the Broadwater area.